class Programmer {
    name: string;
    goodAt: string;

    constructor(name: string, goodAt: string) {
        this.name = name;
        this.goodAt = goodAt;
    }

    info(): string {
        return `姓名：${this.name}，擅长：${this.goodAt}`;
    }
}

class Staff extends Programmer {
    private staffId: number;

    constructor(name: string, goodAt: string, staffId: number) {
        super(name, goodAt);
        this.staffId = staffId;
    }

    public getEmployeeId(): number {
        return this.staffId;
    }
}

let staff1 = new Staff("ShirDon", "Programming", 888);
let res = staff1.info();
console.log(res);
console.log(staff1.getEmployeeId());
// $ tsc TypeScriptExample7.ts
// $ node TypeScriptExample7.js                                                                                                                                                                                                  mc@unknown 10.3 % node
// 姓名：ShirDon，擅长：Programming
// 888